Brain areas in movement

Brain areas in movement

1. Eye movement

   • Oculomotor nerve
   • To shift target onto fovea
   • Cerebellum
     • Reflex adjustment
   • Brainstem
     • VOR
   • Basal ganglia
     • Omnipause neurons
     • Pre-programmed/saccades
   • Posterior parietal cortex
     • Highest centre
   • Frontal eye fields
     • Voluntary movements
   • Paramedian pontine reticular formation
   • Superior colliculus
     • Sensory-motor map for saccades

2. Posture control

   • Selection, effect, maintenance
     • Reflexes only for maintenance
   • Basal ganglia
     • Select basic programmes
   • Reticular formation
     • Generates control programmes
     • Downward connection for BG
   • Cerebellum
     • Calibrates reflexes and central motor programmes

3. Locomotion

   • Reflex chaining not enough
     • Brown (1911)
       • Deafferentation
   • Brain = command centre
     • Projects to spinal locomotor central pattern generators
       • CPG
       • Define gait
       • Malleable
   • Brainstem = speed of locomotion
   • Sensory feedback
     • Can also be used

4. Sensation

   • Primary somatosensory cortex (S1)
     • Receives sensory input
     • Somatotopically organised
     • Map adaptable
       • Makin et al (2013)
     • BA3a/b, 2, 1
   • Other areas
     • PPC
       • Sensorimotor integration
     • Secondary somatosensory cortex
       • Higher order functions

5. Motor systems

   • Primary motor cortex (M1)
     • Map mirrors S1 - somatotopic
     • Betz cells
       • Force
     • Motor learning
       • Retention of memory
         • Galea et al (2011)
         • Reis et al (2009)
     • Main cortical output
       • Skillful movement
   • Cortex
     • Lamina 5/6 output
       • M1
     • Hierarchy
   • Supplementary motor cortex
     • Medial hemisphere surface
     • Habits
   • Dorsal premotor cortex
     • Preparation
   • Ventral premotor cortex
     • Mirror neurons
   • PPC
     • Multimodal integration
       • Maintains body's spatial relationship

6. Cerebellum

   • Organisation
     • Ipsilateral
     • Somatotopic
   • Purkinje cells
     • Decrease communication to cortex
     • LTD
       • Respond to subset of parallel fibres
   • Damage
     • Postural ataxia
     • Intention tremor
     • Hypotonia
   • Motor learning
     • Galea et al (2011)
   • Skill learning
   • Predicting sensory outcomes
     • Miall et al (2007)
     • Schlerf and Diedrichsen (2012)

7. Basal ganglia

   • Selecting action
     • Biased by reward and punishment
   • 2 pathways
     • Inhibitory
     • Dopamine to initiate
     • Parkinson's
       • Underactive direct pathway
       • Loss of SN neurons
       • L-DOPA or DBS
       • Less sensitive to reward
     • Huntingdon's
       • Overactive direct pathway
       • Striatal neuron death
   • Striatum
   • GP
   • Reinforcement learning
     • Reward releases DA
       • Optogenetic method

8. Frontal cortex

   • Dorsolateral PFC
     • Choosing action
     • Wisconsin Card Sort Test
   • Pathways
     • Spinocortical
     • Brain stem systems
   • Views of selection
     • Central Executive
     • Affordance Competition
       • Cisek and Kalaska (2005)
   • Changing mind
     • Cognitive overflow
       • Resulaj et al (2009)
     • Free will
       • Libet et al (1983)
   • Motor learning
     • Taylor et al
     • WM capacity
       • Christou et al (2016)
   • Mental imagery

9. Hippocampus

   • Temporal lobe
   • Relational learning
     • Spatial memory
       • Morris Water Maze
       • Radial arm maze
   • Maguire et al (1997)
   • Spalding et al (2013)
   • Place cells
   • Grid cells

10. PPC

    • Spatial processing/integration
    • Lateralised
      • Neglect
        • Bisiach (1978)
    • LIP
      • Update with eye movement
    • VIP
      • Space/Motion around head
    • MIP
      • Reaching/pointing
    • AIP
      • Active touch